NE556DT STMicroelectronics

NE556 SA556 - SE556 General-purpose dual bipolar timers Features Low turn-off time Maximum operating frequency greater than 500 kHz Timing from microseconds to hours N DIP14 Operates in both astable and monostable (Plastic package) modes Output can source or sink up to 200 mA Adjustable duty cycle TTL compatible D Temperature stability of 0.005% per C SO14 (Plastic micropackage) Description The NE556, SA556 and SE556 dual monolithic timing circuits are highly stable controllers capable of producing accurate time delays or oscillation. In the time delay mode of operation, Pin connections the time is precisely controlled by one external (top view) resistor and capacitor. For a stable operation as an oscillator, the free running frequency and the duty cycle are both accurately controlled with two external resistors and one capacitor. The circuits may be triggered and reset on falling waveforms, and the output structure can source or sink up to 200 mA. January 2009 Rev 2 1/16 www.st.com 16Schematic diagrams NE556 - SA556 - SE556 1 Schematic diagrams Figure 1. Block diagram 3 * () +& /% %& % , +)-, ) . * () 0 2 % % & + +1+ 2 %&% * & %&% Figure 2. Schematic diagram % 0 )0 %& ()/ / 4 * 4 * * * 4 * . 4 * * %& 4 * . * . % 4 * %&% +& /% . * * * * % ()/ / , +) , ) 2/16